This invention relates generally to electronic circuits known as touch controls for electric lamps, and more particularly concerns a touch control circuit which can be manufactured at modest cost, yet which has a long service life and which does not require trimming or adjustment of components once the circuit has been assembled.
Touch control circuits are becoming increasingly popular for use with electric incandescent lamps such as floor lamps and desk lamps used in homes and offices. These touch control circuits make easy the adjustment of light intensity even by physically disabled or impaired persons. When such circuitry is employed, the lamp user need only touch the lamp base or other metal portion of the lamp to turn the lamp on, or to adjust the light coming from the lamp to a low, medium or high intensity. The lamp user is no longer required to fumble in the dark for a small screw switch located inside a shade.
Previous touch control circuits have been offered to the public in a variety of forms. One popular device takes the form of a self-contained unit of modest dimensions and having a male connector for screw insertion into a standard lamp bulb socket, and a standard female socket which accepts the lightbulb. Functionally interposed between the unit male and female sockets is a circuit board bearing the electronic circuitry. At least some such units are expensive to manufacture, and consequently the product sales have been of relatively low volume. In addition, the products of some designs have experienced triac and other component failures at an unacceptably high rate.
It is accordingly the general object of the present invention to provide a touch-control circuit for electric incandescent lamps which can be manufactured at an attractive cost. A related object of the invention is to provide a touch control lamp circuit which does not require trimming or adjustment of circuit components.
Another object is to provide such a circuit in which circuit sensitivity and operational performance is improved.
Yet another object is to provide a touch control circuit which will have extended circuit component performance and life.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.